s 500 won''t start

Hi got home last night during large lightening storm and saw that my parked 2000 s500 all rear lights were on, (brake, reverse & parking) won''t go off even after disconnecting battery, after recarching battery car will crank but not start, also multifunction dislay won''t show anything on dash. think something got fried what to check first. thanks

There isn''t much that you can do... better take it to the dealership.... 

If the car cranks well, then the chances are that this is a fuel related problem. But that covers a lot of ground, from a clogged fuel filter (very cheaphope for that one) to a bad fuel pump (expensive and all too likely in a car that age). It could also be a problem with the carburator. There is also a small chance that it is not fuel but fouled spark plugs or the starter itself, but my bet is on fuel.

But in the end, all these have to be guesses, because I can''t look at your car. You need to take it to a mechanic, and preferably to an old-time mechanic. Most young guys in this business today have never even worked on carburated engines.

Just for your information Mercedes stopped using Carbuerators 30 years ago. 
 
BTW...Have your rear sam checked.  Most likely culprit.

SAM....???

SIGNAL ACQUISITION MODULE.  LOCATED UNDER REAR SEAT ON THE RIGHT SIDE. PART OF THE FUSE BOX.

yup water got to the sam

have been trying to dry it out for a couple of days what a mess, went to dealer to ask what it might cost to replace sam, he didn''t want to answer me whithout checking it out first, anyone know ballpark what I might be lookin at, I just got this car, haven''t even regitered it yet, and it looks like i won''t be for a while, because i spent most of my money getting my dream car that may turn into a nightmare.

THE PART IS AROUND $450.00 DEPENDING ON MARK UP PLUS LABOR.  CHECK YOUR WINDSHIELD DRAINS.  THAT IS THE MOST LIKELY CAUSE OF YOUR ISSUE.  WATER WILL BACK UP WHEN THE DRAINS ARE CLOGGED AND WILL COME IN THROUGH THE BLOWER MOTOR AND WILL RUN TO THE BACK WHERE IT ENTERS THE REAR SAM.  REPLACING THE SAM ON YOUR OWN IS GOING TO BE IMPOSSIBLE.  THE SAM HOLDS IMPORTANT CODING THAT ONLY SDS CAN HANDLE.

Hey, blue would I be able to replace the sam myself, than bring car to dealer and have them program it.
saw this sam on ebay
http://cgi.ebay.com/ebaymotors/OEM-Mercedes-W220-Signal-Aquisition-Module-S320-S430-S_W0QQcmdZViewItemQQ_trksidZp1713Q2em153Q2el1262QQcategoryZ33598QQihZ012QQitemZ220011359960
 
thanks John

also after drying out rear for three days car does start, dash works, just lights in rear not functioning right

YOU MIGHT BE ABLE TO.  NO GUARANTEES.